The Stream Baths
There would be bath houses, a building with stone floor. This building had a drain and would have a fire in the middle of the room. The fire would heat the stones and before long water would be thrown upon them (when they are red hot). This would cause hot steam to rise that would make you sweat. The Vikings would sit down and absorb the heat, this would open their pores, basically cleaning them.
Washing
For a quick wash Vikings would have a bowl of water, the first man would rinse his hair, beard and face. The man would then blow his nose, cleaning out anything inside it into the bowl. After this, it would be passed to the next man who would then too, wash his face and blow his nose. The same bowl would go around the whole room to however many men there were.
Illness
Vikings who became ill were taken away and put in a small tent with water and bread. They would be ignored by everyone else, this was to stop infection. When the ill person regained their health they would come back and rejoin, if they died they would be burned in the tent. Slaves were not considered worth burning, if they died they would be left there for wild creatures and vultures to eat them.